Adjustable t-square



Sept. 20, 1966 A. w. SIBERINI ADJUSTABLE T-SQUARE Filed June 29, 1964FIG. 4 FIG 8 ,42 la 22 Z //////I|||1V////////,,. 2/

INVENTOR. ALFRED W. SIBER/N/ ATTORNEY United States Patent 3,273,246ADJUSTABLE T-SQUARE Alfred W. Siberini, 221 Ivy St., Kearny, NJ. FiledJune 29, 1964, Ser. No. 378,699 10 Claims. (Cl. 33101) This inventionrelates to drafting apparatus, and more particularly, to a T-square witha blade universally adjustable with respect to its head.

T-squares are known in which the head is fixed with respect to itsblade. They are also known in which each head is angularly movable withrespect to its blade. In accordance with my invention, the head is notonly adjustable 'angularly with respect to its blade, but the blade islongitudinally slidable with respect to the head when associatedtherewith in one position and also angularly movable with respectthereto when removed and -re-asso ciated with it in another position.

An object of my invention is to provide an adjustable T-square in whichthe blade is slotted and connected to the head by a thumb screw whichwhen tightened holds it against angular and/or longitudinal movementwith respect to said head.

Another object of my invention is provision of a T- square in which theblade may be slideably mounted with respect to its head when connectedto one face thereof and rotatably mounted with respect to its head whenconnected to the other face thereof, one edge of said other face beingsemi-circular and angularly graduated as a protractor, the divisionsthereof being readable through an aperture in the blade to thereby showthe angular position of said blade with respect to its head.

A further object of my invention is the provision of an adjustableT-square in which the blade is graduated along its edges to function asa ruler and removable from its head.

These and other objects and advantages will become apparent from thefollowing detailed description when taken with the accompanyingdrawings. It will be understood that the drawings .are for purposes ofillustration and do not define the scope or limits of the invention,reference being had for the latter purpose to the appended claims.

In the drawings, wherein like reference characters denote like parts inthe several views:

FIGURE 1 is a perspective view of an adjustable T- square embodying myinvention, wherein the blade is connected to its head for angularmovement therebetween.

FIGURE 2 is a view corresponding to FIGURE 1, but showing the headreversed with respect to its blade and connected thereto so as toprevent any angular movement therebetween.

FIGURE 3 is a plan of a head of the T-square, shown in FIGURE 1, afterthe blade has been removed therefrom.

FIGURE 4 is an edge elevational view of the head as from the bottom ofFIGURE 3.

FIGURE 5 is a side elevational view of the thumb screw which holds thehead and blade together in adjusted position.

FIGURE 6 is a side elevational view of a locking washer which may beused between the head of the thumb screw and the blade of the T-squarewhen the parts are held together.

FIGURE 7 is a full-sized fragmentary plan of the upper or far end, ofthe blade of the T-square, as viewed in FIGURES 1 and 2, from thebottom.

FIGURE 8 is a full-sized section view of the blade on the line VIII-VIIIof FIGURE 2, in the direction of the arrows.

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Referring to the drawings in detail, there is shown a T-square embodyingmy invention comprising a head or butt plate 11, one side of which isslotted as indicated at 12 and the other side of which has a series ofangle or degree graduations 13 along a semi-circular edge portion 14.Edge portion 14 is semi-circular, or extends between 0 and degrees, andthen its ends extend straight, as indicated at 15 and 16, perpendicularto a straight edge portion 17.

Associated with the head 11 is a blade or ruler portion 18, desirablygenerally trapezoidal in section, as indicated most clearly in FIGURE 8,except that the sharp edges along the lower face at the sides aredefined by right angles rather than by acute angles, as would occur ifthe sloping or beveled sides 19 and 21 were continued to the extremelower face. This is in the interest of accuracy so as to have at least aslight thickness at the drawing edges of the blade, rather than havingsaid edges acute in angularity.

The blade section, as shown most clearly in FIGURE 8, corresponds withthe section of the notch or slot 12 in the head, so that said blade maybe slid into said notch and be snugly held therein against any angularmovement with respect to said head, as viewed in FIG- URE 2. However,longitudinal movement between the head and blade is permitted by virtueof the longitudinal slot 22 extending the greater part of the length ofthe blade and of a width sufiicient to receive the shank 23 of a thumbscrew 24. The head 25 of said screw is desirably knurled to facilitateapplication and removal.

The shank 23 of said screw 24, for reception in a threaded aperture 32in the head 11, desirably passes through a washer 26, shaped as shownmost clearly in FIGURES 1, 2 and 6; that is, with its peripheral edgebeveled or sloping as indicated at 27. Said washer is shown disposedbetween the lower surface of the head 25 and the top surface of theblade 18. This construction allows the blade to be adjusted with respectto the head and then tightened in place on said head in an ad justedposition. The edges of the blade 18 are graduated in inches,centimeters, or other desired unit of measurement, as illustrated,thereby adapting said blade to be used as a ruler either with or whenseparated from its head.

The blade 18, instead of being used in position where it extendsperpendicular to the straight edge 17 of the head 11, may be removedfrom the slot 12, after unloosening and removing the thumb screw 24 andassociated washer 26 from the threaded aperture 32, and the headreversed to the position of FIGURE 1 and reconnected by said screw 24 tothe blade 18. Here angular adjustment therebetween is permitted, asbetween the head position shown in full lines, where the relationship isperpendicular, and that indicated with dotted lines, where the head 11has been angled with respect to the blade 18. Such occurs when it isdesired to use the head as a protractor for drawing a line along theblade at an angle other than perpendicular with respect to the straightedge 17 In order to accurately measure the angle through which thisblade is swung with respect to the head, the upper or remote end of theblade as illustrated, has an aperture 28 desirably closed by atransparent plug 29, which may be formed of plastic material or thelike. It desirably carries a hair line 31 engraved thereon so as to lieover a selected angular graduation for setting the blade with resepct tothe head. For that purpose, the hair line 31 is desirably formed on thebottom of the blade plug 29, as viewed in FIGURES 1 and 2, it beingnoted, however, that the blade in FIGURE 7 is a view of the bottom, sothe hair line 31 is there on the top and lies along a diameter of theplug 29 parallel to the side edges of the blade.

From the foregoing disclosure it will be seen that I have devised auseful T-square comprising a head 11, flat on one side, with one edge 17straight and the other edge 14 curved or semi-circular and terminated bystraight portions 15 and 16 erpendicular to said straight edge 17. Thereis a blade 18 associated with said head 11 for completing the T-square.This blade has its side edges beveled, as indicated at 19 and 21, butdesirably not completely to sharp drawing edges. It carries longitudinalgraduations adapting it to function as a ruler or means for measuringthe distance between the straight edge 17 and a selected position on adrawing board, for example. The head 11 has a threaded aperture 32,extending from one face to the other, lying midway on a straight lineextending between the junctions of said terminating portions 15 and 16and the semicircular edge 14. The blade 18 has a slot 22, of a widthcorresponding with the diameter of the aperture 32 and the shank 23 ofthe thumb screw 24, which slot extends from near one end toward theother and terminates at the distance from the other end approximatingthe radius of said semi-circular edge 14. Said other end portion of theblade 18 has an aperture 28 desirably plugged by a piece of transparentplastic 29 desirably cylindrical and carrying a hair line 31 whichnormally lies over a selected angle graduation along the semi-circularedge of the head 11, so that the position of the blade with respect tothe head may be set as desired, when the parts are assembled as viewedin FIGURE 1. When, however, the

thumb screw 24 is removed and the blade 18 taken from the head, fittedin the slot 12 and the screw shank passed through the slot 22 andthreaded into the aperture 32 to hold the blade in place, as viewed inFIGURE 2, then it always stays square with respect to the straight edge17 of the head. However, even then longitudinal adjustment of said blade18 with respect to the head 11 is permitted, as from the position shownin full lines in FIGURE 2 to that indicated in dotted lines in saidfigure.

Having now described my invention in detail in accordance with therequirements of the patent statutes, those skilled in this art will haveno difficulty in making changes or modifications in the individual partsor their relative assembly in order to meet specific requirements orconditions. Such changes and modifications may be made without departingfrom the scope and spirit of the invention, as set forth in thefollowing claims.

I claim:

1. An adjustable T-square comprising a head flat on one side, with oneedge straight, a blade associated with said head for completing theT-square, said head having a threaded aperture, extending from one faceto the other, lying halfway between its ends, said blade having a slotclosed at both ends and of width corresponding with the diameter of saidaperture, a thumb screw with a threaded shank fitted through said slotand into said aperture for holding said blade in place with respect tosaid head, the other side of said head having a groove of sectioncorresponding with that of said blade and into which the latter fitswhen removed from said screw, reversed and slid along the other side ofsaid head, said groove being defined by side edges parallel to a planethrough the axis of said aperture and perpendicular to said straightedge and said screw being removable and reinsertable in the head fromthe opposite face to hold the blade in place, so that said blade when soheld in the groove will always be square with respect to the straightedge of the head.

2. An adjustable T-square as recited in claim 1, wherein the sideedgesof said blade are beveled and the groove correspondingly dovetailed insection.

3. An adjustable T-square as recited in claim 1,

wherein another ide of said head is semi-circular but terminated bystraight portions perpendicular to the straight edge and the threadedaperture lies midway on a straight line extending between the junctionsof said terminating portions with said semi-circular edge.

4. An adjustable T-square as recited in claim 1, wherein the bladecarries length graduations adapting it to function as a ruler.

5. An adjustable T-square as recited in claim 1, wherein said slotextends from near one end toward the other and terminates at a distancefrom the other end approximating the radius of said semi-circular edge.

6. An adjustable T-square as recited in claim 1, wherein another edge ofsaid head is semicircular.

7. An adjustable T-square as recited in claim 6, wherein there are anglegraduations along said semicircular edge, said other end portion of theblade having an aperture alined with said slot and through which saidangle graduations are readable when said blade and head are securedtogether by said screw.

8. An adjustable T-square as recited in claim 7 wherein there is atransparent plug closing said aperture, and a hair line on said plug forreading the angular disposition of said blade with respect to thestraight edge of said head.

9. An adjustable T-square comprising a head flat on one side, with oneedge straight and the other semicircular but terminated by straightportions perpendicular to said straight edge, a blade associated withsaid head for complet-ing the T-square, said blade having its side edgesbeveled and carrying length graduations adapting it to function as aruler, said head having a threaded aperture lying midway ona straightline extending between the junctions of said terminating portions withsaid semicircular edge, said blade having a slot of width correspondingwith the diameter of said aperture, extending from near one end towardthe other end and terminating at a distance from the other endapproximating the radius of said semicircular edge, a thumb screw witha-threaded shank fitted through said slot and into said aperture, anglegraduations along said semicircular edge, said other end portion of theblade having an aperture alined With said slot, transparent plug closingsaid aperture, a hair line on said plug for reading the angulardisposition of said blade with respect to the straight edge of said headwhen said blade and head are secured together by said screw, the otherside of said head having a dovetailed groove of section correspondingwith that of said blade and into which the latter fits when removed fromsaid screw, reversed and slid along the other side of said head, saidgroove having side edges parallel to a plane through the axis of saidaperture and perpendicular to said straight edge.

10. An adjustable T-square comprising a head flat on one side, with oneedge straight and the other curved, a blade associated with said headfor completing the T- square, said blade having its side edges carryinglength graduations adapting it to function as a ruler, said head havinga threaded aperture extending through said head and lying midway of saidhead, said blade having a slot of width corresponding with the diameterof said aperture, extending from near one end toward the other end, athumb screw with a threaded shank fitted through said slot and into saidaperture, angle graduations along said curved edge, said other endportion of the blade having an aperture alined with said slot forreading the angular disposition of said blade with respect to thestraight edge of said head when said blade and head are secured togetherby said screw, the other side of said head having a groove of sectioncorresponding with that of said blade and into which the latter fitswhen removed from said screw, reversed and slid along the other side ofsaid head, said groove having side edges parallel to a plane through theaxis of said aperture and perpendicular to said straight edge and saidscrew being removable and reinsertable in the head from the side of thehead having References Cited by the Examiner UNITED STATES PATENTS9/1916 Cruzen 33-102 4/1917 Helden 33-102 6 1,636,637 7/1927 Hutchinson33-102 1,655,638 1/1928 West 33-99 2,179,658 11/1939 Gallagher 33-103 XFOREIGN PATENTS 520,566 2/1921 France 347,360 8/1960 Switzerland.

LEONARD FORMAN, Primary Examiner.

1,243,786 10/1917 White 33-103 10 H. N. HAROIAN, Assisant Examiner.

1. AN ADJUSTABLE T-SQUARE COMPRISING A HEAD FLAT ON ONE SIE, WITH ONEEDGE STRAIGHT, A BALDE ASSOCIATED WITH SAID HEAD FOR COMPLETING THET-SQUARE, SAID HEAD HAVING A THREADED APERTURE, EXTENDING FROM ONE FACETO THE OTHER, LYING HALFWAY BETWEEN ITS ENDS, SAID BLADE HAVING A SLOTCLOSED AT BOTH ENDS AND OF WIDTH CORRESPONDING WITH THE DIAMETER OF SAIDAPERTURE, A THUMB SCREW WITH A THREADED SHANK FITTED THROUGH SAID SLOTAND INTO SAID APERTURE FOR HOLDING SAID BLADE IN PLACE WITH RESPECT TOSAID HEAD, THE OTHER SIDE OF SAID HEAD HAVING A GROOVE OF SECTIONCORRESPONDING WITH THAT OF SAID BLADE AND INTO WHICH THE LATER FITS WHENREMOVED FROM SAID SCREW, REVERSED AND SLID ALONG THE OTHER SIDE OF SAIDHEAD, SAID GROOVE BEING DEFINED BY SAID EDGES PARALLEL TO A PLANETHROUGH THE AXIS OF SAID APERTURE AND PERPENDICULAR TO SAID STRAIGHTEDGE AND SAID SCREW BEING REMOVABLE AND REINSERTABLE IN THE HEAD FROMTHE OPPOSITE FACE TO HOLD THE BLADE IN PLACE, SO THAT SAID BLADE WHEN SOHELD IN THE GROOVE WILL ALWAYS BE SQUARE WITH RESPECT TO THE THE GROOVETHEREIN AND THROUGH THE SLOT TO HOLD THE BLADE STRAIGHT EDGE OF THEHEAD.